The ability to controllably interconnect metallic nanoparticles with nanometer scale metallic junctions, enabling charge transfer at optical frequencies, while simultaneously producing such nanostructures in macroscale quantities has proven difficult. A need exists to surmount this problem.
One group has reported experiments demonstrating that gold nanorods can be welded together into oligomers (Gonza□lez-Rubio et al., Nano Lett. 2015, 15, 8282-8288.) The specificity and yield of welded oligomers using this approach was very low, with CTP absorbance peaks <0.1 and full-width-at-half-maximum (fwhm)>>500 nm. These oligomer experiments do not demonstrate the controlled concatenation and welding of the nanorods but instead show random agglomeration, which is expected upon exposure to an intense laser pulse. Moreover, this laser-based technique lacked control of the configuration (or orientation) by which the nanorods assemble. Consequently, there remains a significant need for alternative approaches to efficiently and controllably produce large, high-quality yields of welded nanorod structures.